This account of the Lewis and Clark Expedition, published in 1814, is based on the detailed journals kept by Captains Meriwether Lewis and William Clark, the leaders of expedition. The book begins with “Life of Captain Lewis,” written by Thomas Jefferson, which reproduces Jefferson’s detailed instructions to Lewis regarding the goals of the expedition. “The object of your mission is to explore the Missouri River, and such principal streams of it, as, by its course and communication with the waters of the Pacific Ocean, whether the Columbia, Oregan [sic ...

When the United States purchased Louisiana from France in April 1803, the extent and character of the land was uncharted. On May 14, 1804, Captains Meriwether Lewis and William Clark set out on an expedition to explore the new territory that would fundamentally change Americans’ conceptions of their country. Clark served as the expedition’s principal cartographer. After completing the three-year journey from St. Louis to the Pacific Ocean and back, Clark worked at compiling a comprehensive map of the American West, using his personal knowledge and information gleaned from ...